How appendages, like plant leaves or animal limbs, develop asymmetric shapes remains a fundamental question in biology. Although ongoing research has revealed the genetic regulation of organ pattern formation, how gene activity ultimately directs organ shape remains unclear. The leaf, as a representative plant lateral organ, provides an excellent model to study the establishment of organ asymmetry.
Recently, an interdisciplinary collaborative effort spearheaded by Drs. JIAO Yuling from Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and LONG Mian from Institute of Mechanics, Chinese Academy of Sciences, shed light on this biological shape formation process.
The team showed that leaf dorsoventral (adaxial-abaxial) polarity signals lead to mechanical heterogeneity of the cell wall, related to the methyl-esterification of cell-wall pectins. Numerical simulations predicate that mechanical heterogeneity is sufficient to produce the asymmetry seen in planar leaves. A real surprise of this investigation was that altering pectin methyl-esterification, and therefore cell wall mechanical properties, support this model and lead to polar changes in gene expression. Thus, mechanical heterogeneity within tissue may underlie organ shape asymmetry.
This study entitled “Mechanical regulation of organ asymmetry in leaves” has been published online in the
Nature Plants (
DOI: 10.1038/s41477-017-0008-6) on September 4
st.
This study was supported by the the National Basic Research Program of China (973 Program), the National Natural Science Foundation of China, the National Program for Support of Top-Notch Young Professionals, and the State Key Laboratory of Plant Genomics.
Figure. Polarity genes and auxin regulate leaf polarity patterning through mechanical signals (Image by IGDB)
Contact:
Dr. JIAO Yuling
